Because it clearly states in Maryland state law (not an opinion by anyone) that it must be dated withing 2 years of the application. No vagueness at all when it is clearly written in law, and if your instructor doesn't know that, then perhaps you might want to look for a new instructor?
Please understand I'm not disagreeing with you! Just reporting my experience in trying to be clear on the topic, and how easily the low-hanging-fruit of that info can lead an intelligent, web-savvy, cynical, skeptical resident of Maryland to none the less end up with bad info. I'm beginning to realize how common a problem that is, when the MSP's various public faces are the main sources for most of that (since few people head off to read the actual law, assuming their certified instructors and the Trooper they talked to had it right). Yes, this drives me to much more support for several of the bills introduced the other day - the ones aimed at simply freeing us all from the tangled, capricious mess that MD hands us in this regard. Thanks for making me do an end-around the usual sources, and actually read the law.